[elpa] externals/xr updated (35dbbeb -> 2a82e8d)

[Mattias Engdegård]

mattiase pushed a change to branch externals/xr.

      from  35dbbeb   Increment version to 1.19
       new  1c4934d   Add github auto-test infrastructure
       new  a655991   Use correct text quoting in message about . in 
file-matching regexp
       new  461dce1   Remove dead function xr--matches-nonempty-only-p
       new  77ad0d6   syntax and category always match non-empty, for bos/eos 
anchor check
       new  17d7599   Improved test coverage with some omitted cases
       new  9b69cc7   Run automatic tests on Emacs 27.1
       new  c7c861f   Describe diagnostics in README (taken from relint/README)
       new  ee8ac4a   Minor looking-at optimisation
       new  6f2e516   Comment update
       new  32546a7   Fix character alternative duplication removal
       new  a444d8c   Explain why we are not using rx in one place
       new  2a82e8d   Increment version to 1.20


Summary of changes:
 .github/workflows/test.yml |  30 +++++++
 Makefile                   |  19 +++++
 README                     | 196 +++++++++++++++++++++++++++++++++++++++++++++
 xr-test.el                 |  51 +++++++++++-
 xr.el                      | 140 ++++++++++++++------------------
 5 files changed, 354 insertions(+), 82 deletions(-)
 create mode 100644 .github/workflows/test.yml
 create mode 100644 Makefile